#define _CRT_SECURE_NO_WARNINGS 1

#include <stdio.h>
#include <math.h>

int main() {
    int n, m;
    while (scanf("%d %d", &n, &m) != EOF) {
        double tmp = (double)n;
        double sum = 0;
        while (m--)
        {
            sum += tmp;
            tmp = sqrt(tmp);
        }
        printf("%.2lf\n", sum);
    }
    return 0;
}